Sudden cardiac arrest (SCA) is the leading cause of death for hemodialysis patients, and it is estimated that up to 23% of these SCA occur within outpatient dialysis clinics. Even though SCAs in dialysis clinics are wit- nessed by trained health care professionals with access to resuscitation equipment, post-SCA survival is only 8%. Potential reasons for these poor outcomes include (1) a low proportion of ventricular tachyarrhythmia car- diac arrests, which are more readily reversible; (2) underutilization of automated external defibrillators (AEDs); and (3) sub-optimal performance of bystander cardiopulmonary resuscitation (CPR) by clinic staff. However, the contribution of these factors toward poor SCA survival in dialysis patients has not been evaluated. The overall objective of this application is to address these knowledge gaps regarding current resuscitation practic- es and to identify barriers to optimal resuscitation within dialysis clinics, with the long-term goal of improving survival for hemodialysis patients suffering from SCA. Based on preliminary data, the central hypothesis is that ventricular tachyarrhythmias are common in dialysis units, but CPR and AED utilization within dialysis clinics are suboptimal due to a variety of modifiable barriers. This hypothesis will be examined using the North Caroli- na Cardiac Arrest Registry to Enhance Survival (NC CARES), an innovative prospective clinical registry of out- of-hospital cardiac arrest patients, to identify and characterize SCA events occurring within outpatient dialysis facilities in order to accomplish the first three inter-related specific aims: (1) to identify the proportion of events presenting with an initial shockable ventricular tachyarrhythmia in order to determine the potential for success- fully treating SCA in dialysis clinics; (2) to define current practices in SCA resuscitation by hemodialysis clinic staff, including provision of CPR and use of AEDs, and compare these practices with those used for SCA in other non-dialysis outpatient health care facilities; and (3) to determine the relationships between ventricular arrhythmias, cardiac arrest resuscitation practices, and patient outcomes in hemodialysis clinics. The final aim of this proposal will be to conduct qualitative interviews with dialysis clinic staff to gain perspectives on poten- tial facilitators and barriers to CPR and AED use in dialysis clinics and subsequently develop a validated sur- vey tool that can be used in future research steps. This study will be the first thorough evaluation of SCA re- suscitation efforts in dialysis clinics and their association with outcomes. The findings will both define points for potential effective intervention and create a new validated survey instrument that can guide the development of tailored interventions to improve resuscitation efforts. Although limited in scope, consistent with the R03 mech- anism, these investigations have the potential to suggest simple, easily implemented interventions that will im- prove resuscitation and reduce mortality for thousands of dialysis patients.